东海盆地的变质岩

Metamorphic Rocks in the East China Sea Basin

东海盆地处于欧亚板块和太平洋板块的交接部位,是全球岩石圈结构和动力学机制研究中涉及众多基础问题的关键地区。它的生成及发展对深化中国东南陆缘地区地壳构造演化的认识,且为能源勘查,研究海平面变化,预测自然灾害,保护环境及国土主权均有重大意义。就其构造机制及性质说法不一,有待商榷。该盆地内已钻井30余口,随改革开放以来,局部凹陷对外公开招标,已施工10余口井,涉及变质岩的仅2口井。变质岩为黑云斜长片麻岩类,原岩恢复为变质火成岩(中性侵入岩,包括石英闪长岩及其相关的浅成岩),属吕梁期,原岩经多期变质或混合岩化作用所致,是中国大陆的自然延伸部位。

The East China Sea Basin is located in the juncture between the Eurasian plate and the Pacificplate. It is the key area involving numerous fundamental problems in the study of the global lithosphere structure and dynamic mechanism. The study of its formation and development will promote our understanding of the crustal structural evolution of the southeastern continental marginal area of China, and will have great significance in energy investigation,sea level change study,natural disaster prediction, environment protection and territory sovereignty defense. Of the more than ten boreholes drilled in the local depression within this sea basin, two have encountered metamorphic rocks, which are biotiteplagioclase-gneiss in composition. The primary rock is a metamorphosed igneous rock (intermediate intrusive rocks including quartz diortte and its related hypabyssal rocks) of the Luliang Stage which has experienced multi-stage metamorphism and migmatization.